In patients with diabetic macular edema (DME), aflibercept and ranibizumab are more effective than bevacizumab in preventing disease persistence, but each drug can lead to substantial gains in vision, according to a post hoc analysis of a randomized trial, according to a report Reuters Health.

Adam R. Glassman of the Jaeb Center for Health Research, Tampa, Florida, and colleagues came to these conclusions after studying patients with central-involved DME who had been treated with these anti-vascular endothelial growth factor (VEGF) agents. The findings were published online February 1 in JAMA Ophthalmology,

Among the 660 eyes initially randomized to up to six monthly injections of aflibercept, bevacizumab or ranibizumab, 114 were excluded from the analysis because of factors including missed visits and alternative treatment for DME.

Persistent DME through 24 weeks was significantly more common with bevacizumab (65.6%) than aflibercept (31.6%) or ranibizumab (41.5%). At two years, the corresponding rates were 68.2%, 44.2% and 54.5%.

However, at 2 years, the percentage of eyes gaining 10 or more letters from baseline did not differ significantly between eyes with or without chronic persistent DME. In fact, overall, only three eyes with chronic persistent DME and two without persistent DME lost at least 10 letters. Stratification by baseline visual acuity yielded consistent results.

“One limitation of this study,” the researchers concede, “is that the primary comparisons are based on groups determined by response to treatment, which is not a randomized comparison.”

Glassman told Reuters Health by email, “These analyses provide additional confidence that macular edema may continue to improve even following 6 or more monthly anti-VEGF injections for central-involved DME with vision loss. Considering vision gains are common and substantial vision loss is rare even among eyes with persistent DME, caution may be warranted when considering switching to alternative therapies after three or more injections.”

Dr. Rajendra S. Apte, of Washington University School of Medicine, St. Louis, Missouri, and author of an accompanying editorial, told Reuters Health by email, “The important take home message is that in eyes treated with intravitreal anti-VEGF for DME, there is continued improvement in vision and increasing resolution of edema from week 12 to 24 of therapy and robust gains in vision through 2 years of therapy irrespective of the specific anti-VEGF agent chosen.”

Dr. Apte added, “A more granular analysis suggests that aflibercept may be better than bevacizumab at improving anatomic outcomes at 24 weeks and 2 years.” In his editorial he explains that “the study may not be powered to detect such differences between aflibercept and ranibizumab at 24 weeks.”